body {
    font-family: system-ui, -apple-system, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: #f3f4f6;
    color: #1f2937;
}
.container {
    text-align: center;
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}
h1 { color: #2563eb; }
button {
    background-color: #2563eb;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 1rem;
    margin-top: 1rem;
}
button:hover { background-color: #1d4ed8; }